Download Brain death declaration in children

Brain death declaration in
children
Dr Lokesh Lingappa
Consultant Paediatric Neurologist
Rainbow Children’s Hospital and
Perinatal Centre, Hyderabad
outline
•
•
•
•
•
Limitations of current guidelines
Testing process
Are there differences adult/pediatric
Problems of newborn testing
Fallacies in intepretation of signs and testing
results
Key message
• The diagnosis of brain death should remain a
clinical one to be made at the bedside by
knowledgeable physicians who, in concert
with grieving families, make the most
agonizing of all life’s events (the death of a
child) as bearable as possible for all
concerned.
• Freeman JM, Ferry PC. New Brain Death
Guidelines in Children
Understanding limitations of pediatric
brain death guidelines
• Guidelines are 20 years old
• Relied heavily upon EEG testing
• Guidelines did not specifically address the trauma
population
• Guidelines were based upon limited clinical
experience at the time of publication
• Guidelines were based upon age criteria
• No guidelines for neurologic death in neonates
• Waiting times have never been validated
History
• Determination of cause of death is necessary
to ensure the absence of treatable or
reversible conditions (ie, toxic or metabolic
disorders, hypothermia, hypotension, or
surgically remediable conditions).
Primary requirement
• Irreversibility of brain function cessation is
recognized
• Cause of coma is established and is sufficient
to account for the loss of brain function
• Possibility of recovery of any brain function is
excluded
• Cessation of brain function persists for an
appropriate period of observation or trial of
therapy
Diagnostic criteria
• Cessation of all brain function is recognized.
• Cerebral functions are absent (ie,
unresponsiveness)
• Brainstem functions are absent:
1. Pupillary light reflex
2. Corneal reflex
3. Oculocephalic/oculovestibular reflex
4. Oropharyngeal reflex
5. Respiratory (apnea using an accepted apnea
testing procedure)
Confounding factors
•
•
•
•
•
Complicating conditions are excluded
Drug and metabolic intoxication
Hypothermia
Circulatory shock
The patient has been monitored for an
appropriate observation period
Brainstem testing
Without confirmatory tests
With confirmatory tests
• 12 hours when the etiology
of the irreversible condition
is well established
• 24 hours for anoxic injury to
the brain
• EEG: Irreversible loss of cortical
functions with ECS, together with
the clinical findings of absent
brainstem functions, confirms the
diagnosis of brain death.
• CBF: Absent CBF demonstrated by
radionuclide scanning or
intracranial 4-vessel cerebral
angiography in conjunction with
clinical determination of absence
of all brain function for at least 6
hours is diagnostic of brain death
Age dependent Observation period
age
Hours between Recommended number
2 examination of EEGs
7 days to 2 months
48
2
2 months to 1 year
24
2
Beyond 1 year
12
None needed
Brain death and organ donation
Rainbow data 2009 29/79
Head injury
3
Near Drowning
2
CNS infection
9
Asphyxia
1
Metabolic disorders
9
Cerebrovascular disorders
1
Miscellaneous
4
Neonatal brain death
Neurologic death in the neonate
• “Brain death can be diagnosed in the term infant,
even at less than 7 days of age. An observation
period of 48 hours is recommended to confirm
the diagnosis. If an EEG is isoelectric or if a CBF
study shows no flow, then the observation period
can be shortened to 24 hours.”
• Ashwal. Brain death in the newborn. Clinics in
Perinatology 1997;24:859-879
Brain death in the neonate
• The younger the child, the more one needs to
exercise caution in determining brain death
• A second opinion from a colleague in pediatric
critical care or someone who is specialized in the
neurosciences is reasonable
• Physical examination criteria may require a longer
observation time based upon mechanism of
cerebral injury
• Use of ancillary test may be beneficial, but may
also confuse the issue in the neonate
• The absence of any form of repetitive,
sustained, purposeful activity on serial
examinations must be documented; likewise,
brain death must be differentiated from other
states of unconsciousness, such as the
vegetative state
preterm and term neonates
• several of the cranial nerve responses are not
fully developed.
• pupillary light reflex is absent before 29 to 30
weeks’ gestation,
• oculocephalic reflex may not be elicited
before 32 weeks’ gestation
• Term and preterm infants are difficult to
examine because their smallness makes it
technically difficult to assess
Preterm and neonate
• Assessment of pupillary reactivity can be
compromised difficulties in gaining access –
incubator, by corneal injury, retinal
hemorrhages, and other anatomical factors
(swelling or partial fusion of the eyelids)
• smaller size of the pupils in newborns- make
assessment of the loss of pupillary reactivity
troublesome
Preterm and neonate
• Assessing the caloric response adequately more
difficult in neonates with a small external ear canal;
• both the oculocephalic (doll’s eye) and oculovestibular
(caloric) reflex should always be examined
• corneal reflex- easiest brain stem reflex to examine in
neonates and infants, it is often the least reliable
• Contact irritation, dehydration and maceration of the
cornea, use of lubricant drops, and use of analgesic
medications often adversely affect tactile sensory
information
MRI and CT of Neonates -HIE
Neuroimaging in Decision process
Neonatal CT
Follow up CT brain
ANCILLARY TESTING
Considerations when diagnosing brain
death in children
• Many times the cause of the child’s neurologic
demise is known
• Based upon presentation and examination many
times we know that there will be no hope for
survival or if the child does survive, the outcome
will be dismal
• The waiting period may be extended or
decreased depending upon social and family
related issues
Ancillary testing
• Ancillary test that may aid in the diagnosis of
brain death
• EEG
• Cerebral angiography
• Radionuclide Scans
• Brainstem evoked responses
• Doppler sonography
Ancillary testing
• Ancillary tests may aid in the diagnosis of brain
death
– Ancillary tests can provide additional information to
help confirm brain death in situations where clinical
examination and apnea testing are not feasible or
cannot be completed because of undue circumstance
– Facial injury
– Acute lung injury
– Cardiovascular instability
Ancillary testing
Ancillary tests are not mandatory
• Ancillary tests may provide another layer of
comfort to the physician who is
uncomfortable declaring brain death on
clinical exam alone
• Ancillary tests may reduce observation periods
thus increasing potential for retrieving viable
transplant tissue
• Ancillary tests may also delay or prolong
observation period
Recommendation for EEG
• the American Electroencephalographic Society
retrospectively surveyed 1665 patients with
electrocerebral silence (ECS), that is, no
evidence of brain electrical activity greater
than 2 µV between electrode pairs placed at a
distance of 10 cm or more, who were in
various levels of coma
• Only 3 of the 1665 patients recovered
cerebral function
EEG in infants and children
• shorter interelectrode distances;
• external artifacts in newborn ICUs and PICUs;
• Distances between the heart and the brain, making
the electrocardiographic contribution
disproportionately large
• reduced amplitude of cortical potentials in preterm
and term neonates
• longer duration of the effect of depressant
medications
• greater tendency for suppression burst patterns in
infants with neurological disorders
Need for EEG
• Two cases of acute inflammatory
demyelinating polyradiculoneuropathy have at satisfied the clinical criteria for brain death
but had preserved EEG activity
• EEG has an important role in the confirmation
of brain death in such cases
Electrocerebral silence
EEG contd
• EEG patterns may show low-voltage theta or
beta activity or intermittent spindle activity
• Such activity in functionally dead brains may
persist for days
• Data from several studies indicate that the initial
EEG in brain dead children is isoelectric in 51% to
100% of patients (mean 83%).
• In most children who initially have EEG activity,
follow-up studies usually show evolution to ECS
• Typically, when the initial EEG
EEG contd
• ECS may occur soon after an infant or a child has
had a cardiac arrest.
• In infants in whom the initial EEG (typically
obtained 8-10 hours after cardiac arrest) showed
ECS, a repeat study 12 to 24 hours later may
show diffuse low-voltage activity
• Most of these infants die of complications - acute
catastrophic injury; the remaining survivors
permanent vegetative or minimally conscious
state
EEG and drugs
• children, the most common medications causing
reversible loss of brain electrocortical activity
include barbiturates (eg, phenobarbital),
benzodiazepines, narcotics, and certain
• intravenous (thiopental, ketamine, midazolam)
and inhalation (halothane and isoflurane)
anesthetics.
• Data from a study in 92 children indicated that
therapeutic levels of phenobarbital (ie, 15-40
μg/mL) do not affect the EEG
Need for repeat EEG
• Data on 37 of 53 brain-dead newborns in whom EEGs
were performed
• ECS (n = 21), very low voltage (n = 13), burst
suppression (n = 1), seizure activity (n = 1), and normal
activity (n = 1).
• Almost all patients whose first EEG showed ECS had
ECS on the second study, and most patients who did
not show ECS on the first EEG did so on a repeat study
• The data suggest that only a single EEG showing ECS is
necessary to confirm brain death, provided the results
of the examination remain unchanged
Cerebral blood flow studies
• The absence of CBF in brain death is due
primarily to low cerebral perfusion pressure
and secondarily to release of vasoconstrictors
• from vascular smooth muscle
HMPO SPECT
Cerebral blood flow-neonatal issues
• Newborns have patent sutures and an open
fontanel, increases in ICP after acute injury are
not significant
• cascade of herniation from increased ICP and
reduced cerebral perfusion is less likely to occur
in newborns
• Brain death can be diagnosed in newborns (even
when younger than 7 days) if physician is aware
of the limitations of the clinical examination and
laboratory testing
Institutional Guidelines
• Does a policy regarding declaration of death exist in your
institution? Policy should provide guidelines allowing
flexibility and individuality for each child and their family
• Decisions regarding determination of brain death should be
left to the physician’s discretion within evolving standards
of medical care
• Who declares brain death in your institution?
• Concentrate your efforts on educating these individuals and
involve them in the establishment of institutional
guidelines
Take home messages
Neurologic death occurs in children
• There are no unique legal issues in determining neurologic
death in children
• Neurologic death is a clinical diagnosis
• Ancillary studies are not mandatory, however they can assist in
determining neurologic death in certain situations
• Ancillary studies can reduce or prolong the recommended
observation period
• Observation periods have never been validated and are meant
to serve as guidelines only
• Neurologic death can occur and be diagnosed in infants less
than 7 days of age
Thank you
•
•
•
•
•
•
•
One Class III study of 144 patients pronounced
brain dead found 55% (95% confidence interval
[CI] 47–63) of patients had retained plantar reflexes,
either flexion or “stimulation induced undulating toe
flexion.”22 Another study documented plantar flexion
and flexion synergy bilaterally that persisted for
32 hours after the determination of brain death.23
ApneaTesting
• Absence of a breathing drive.
• Prerequisites: 1) normotension, 2)
normothermia,
• 3) euvolemia, 4) eucapnia
• (PaCO2 35–45 mm Hg), 5) absence of
• hypoxia, and
• Procedure:
• • Adjust vasopressors to a systolic blood
• pressure 100 mm Hg.
•
Neurology 74 8, 2010
Preoxygenate for at least 10 minutes with 100%
oxygen to a PaO2 200 mm Hg
• 10 breaths per minute- eucapnia
• Reduce PEEP to 5 cm H2O (oxygen desaturation
with decreasing PEEP may suggest difficulty with
apnea testing).
• SpO2> 95%, obtain a baseline blood gas (PaO2,
PaCO2, pH, bicarbonate, base excess)
• Disconnect the patient from the ventilator
Preserve oxygenation (e.g., place an insufflation
catheter through the endotracheal tube and close
to the level of the carina and deliver 100% O2 at
6 L/min).
• Look for respiratory movements - 8–10 minutes.
• Abort if systolic blood pressure decreases to 90
mm Hg.
• Abort if oxygen saturation measured by pulse
oximetry is 85% for 30 seconds.
• Retry procedure with T-piece, CPAP 10 cm H2O,
and 100% O2 12L/min
• If no respiratory drive- repeat blood gas after
approximately 8 minutes.
• • If respiratory movements are absent and
arterial PCO2 is 60 mm Hg (or 20 mm Hg increase
in arterial PCO2), the apnea test result is positive
• • If test is inconclusive- patient is
hemodynamically stable, it may be repeated for a
longer period of time (10–15 minutes)
• after the patient is again adequately
preoxygenated.
Take home messages
• Diagnosing brain death is not different in
children as compared to adult
• Newborn 34 week and above can be reliably
daignosed to have brain death within first
week of life
• Most newborn withdrawal of care is based on
future poor neurologic outcome rather than
brain death
• Most common ancillary testing required is EEG